Expansion joint



March 21, 1933. A. c. FFFFF ER NSION JOINT Patented 'Mar. 21, 1933UNITED STATES PATENT OFFICE ALBERT C. FISCHER, OF CHICAGO, ILLINOIS,ASSIGNOB TO THE PHILIP CAREY mmr- FACTURI'NG COMPANY, A CORPORATION OFOHIO EXPANSION Jom'r Application filed August 21, 1926, Serial 170.130,683. Renewed Ray 9, 1882.

My present invention relates in general to construction material for usein expansion joints for compensating for expanslon and contraction inconcrete and the like structures, and has particular reference to apreformed expansion joint strip especial- 1 adapted for use in concreteroadways for the above outlined purposes.

The primary object of my invention'isto.

provide a preformed strip which will ofier certain compressible, orrather elastic quallties so as to be readily compressible, compensatingfor expansion in the concrete, and readily elastic, compensating forcontraction of the concrete. In other words, when the concrete expandsit is necessary that the strip be more or less-readily compressible inorder to compensate for the expansion, and when the concrete contractsthe strip should be suificiently elastic to fill the space in the jointso as not to leave crevices or spaces in which refuse will collect,which would have a tendency to destroy the functioning powers of thejoint. Other objects and advantages will appear as the description nowproceeds.

This application is a continuation in art of application Serial N 0.336,713, filed 0v. 8, 1919. With reference to the accompanying drawing,Figure 1 is a perspective view of a portion of an expansion joint stripmade in accordance with my present improvement.

Figure 2 is a perspective view of the strip in p ace between twoconfronting sections of a concrete roadway as an example.

Figure 3 is a perspective view of a portion of a strip, showing onedeformable condition in the perforated structure, as the result of theapplication of presure to the sides of the joint.

Figure 4 is a perspective view of a portion of an expansion joint stripshowing the deformable condition of the perforated 45 structure of thestrip as a result of applicaa portion thereof. This strip may be pro-.elasticity such as rubber,

tion of pressure to the top or crown of the strip. I

Referring now to the drawingin detail. 5 represents the preformed strip,or rather duced from various materials suitable for the purpose,particularly some material or a composition of materials which willdevelop compressible and expansible qualities or at least having theinherent qualities of so that the same will readily compress upon theapplication of pressure and expand upon the release of pressure andassume its preformed normal dimensions. In most cases a strip of thisnature, at least as. anexpansion oint for concrete roadways, maybe maderanging from to 1 inch in thickness, 4 inches in depth and about 5 feetlong. These dimensions are simply illustrative of the form of the stripand must not be considered as controlling in every instance, as thedimensions of the strip have little if anything to'do with the novelfeatures of the invention, except that in most every instance the stripwill be produced in this. general figuration.

A material suitable for the p ose comprises a rubber composition,whicmay be produced from to per cent of bituminous material, preferablyblown asphalt or the like oxidized material, or even as halt flux, orany other such residual oil 0 this general character, combined withrubber latex, dissolved rubber, dissolved rubber scrap 10 to 25 percent, or any such materials may be used providing the resultant pro uotwill have considerable elasticity and compressibility. The idea beingthat after once molded l or otherwise shaped it should not beover-sensitive to changes in temperature, so that it will not becomebrittle in cold weather, nor should it have a tendency to ooze or flowin warm weather. As a matter of fact the chan in the physicalcharacteristics of the strip,

dueto variathe case of a so-cal developing the longitudinal surfacetions in temperature, able, at least hardl any more so than in ed solidrubber vehicle tire. v

In some cases I may desire to use a small percentage of fillingmaterial, say about 5 per cent finely divided fibrous material tocheapen the production of the strip and add certain binding qualities tothe other materials used.

I do not consider that the composition of the strip has anything to dowithv my invention other than to make it clear just what qualities thestrip is capable of producing, so that it may adapt itself to the use to,which it is to be applied.

Having produced a strlp of this character I will proceed toperforate'the same, as at 6, so that the final development of the stripis in the nature of a perforated preformed expansion joint strip. Thestrip will be installed as is customary with preformed expansion joints,between sections A and B of the concrete roadwa with the crown of thestrip usually instal ed flush with the surface of the concrete.

The most satisfactory way to install the strip would be to support it oned e, so that the concrete can be poured aroun the same. As thusinstalled the concrete will provide a sealin medium for the perforationsthus trapped air pockets throughout the joint, which will thus developwhat in reality results in a pneumatic joint.

Upon expansion of the concrete sections A and B considerable pressurewill be developed on the sides 0 the joint, and the pneumatic qualitiesof the joint will function to absorb this pressure so to speak, which,together with the perforations, will enable the joint to assume whateverdeformable fi ration will result from the a plication 0 such pressure.In other wor s, as best shown in Figure 2, the perforations, whileordinarily tubular, will change their shape due to the outer ends of thesame spreading and the inner diameter tending to compress. This resultis clearly shown in Figure 2 and again shown in Figure 3. For instance,as shown at 7 the outer diameter of the perforations are spread and theinner diameter is brought together, as at 8. As stated, this is a resultof pressure applied to the sides of the joint.

As a result of pressure applied to the crown of the joint the rforationswill become elongated in a p ane horizontal with of the concrete, andthis result is clearly shown in Figure 4, the perforations in this casebeing oval shaped,

I as shown at 9.

With the joint constructed in accordance with the present invention I donot have to rel so much on the material itself to deve op the cushioningefiect,

will, hardly be notice as the perfora tions will aid in bringing aboutthe results required, at the same time it must be remembered that theperforations would only function when made in a strip, the material ofwhich having the necessary qualities to cooperate with the perforationsfor this purpose.

In the event that any difficulty is experienced in the poured concreteentering the perforations 6 in the strip 5 necessary precautions may betaken to prevent the same, and in this connection I might call attentionto the possibilities of using an installing device for this purpose, orelse prior to installation the strip may be "treated with a light filmof some mastic adhesive softer than the material of the strip, so as toclose the perforations at least so far as danger of the concreteentering the same is concerned, or else in lieu of this mastic layer arelatively thin sheet of any material suitable to seal the perforations,at least until the concrete is set, may be used.

I claim:

1. A rubber-like expansion joint having perforations in the thicknessthereof, said perforations being deformable upon the application ofpressure to the joint, and coopcrating with the material of the joint asa cushioning means for compensating for expension and contraction in theconcrete construction in which the joint is installed.

2. Expansion joint, comprising a preformed rubber-like strip havingperforations in the thickness thereof, said perforations providing airpockets in the joint when the same is installed between concretesections.

3. A paving structure comprising rigid sections, and an expansion stripinserted between the ends of the rigid sections, said expansion stripbeing perforated with a series of openings extending through thethickness of the strip.

4. A paving structure comprising rigid sections, and a preformedbituminous joint strip inserted between the ends of the rigid sections,said expansion joint being perforated with a series of openingsextending through the thickness of the strip.

5. A paving structure comprising rigid concrete paving sections, and aperforated elastic expansion joint inserted between the sections.

6. In a paving, adjacent construction members, a space between saidmembers, means in said space closing the space adjacent to the top ofthe pavement and filler means below said first mentioned means filling aportion of the space between the adjacent members, all so arranged thatthere is a space between the first mentioned means and the secondmentioned means so that both of said means may, under compression byexpansion of the adjacent members, he moved toward each other.

7. In a paving construction, adjacent paving blocks, a space betweensaiti adja- 5 cent locks, means partially space, all so arranged thatthere is a space hetneen upper and lower portions of the filler, andmeans whereby movement towaifl each other may be permitted undercompres- W sion by reason of expansion of the adjacent constructionmembers.

Signed at Chicago, Illinois, this 17th day of August, 1926.

ALBERT C. FISCHER.

